Boiler and the like



T. E. MURRAY ETAL 1,772

BOILER AND THE LIKE Original Fi led June 13, 1924 3 Sheets-Sheet 1 L M 1 5 1 n Md 5 A .V Ill 77/04/45 5 M01684); J!- Frecufa/"s.

' 2 1 W g /ATTORNEYS wIIIIIII/I/l/Il/IIII/IIII/IIII///0 IIIIIIIIIIIVIIAVAIIIII 7!: IfflliflllllIl/Il/I/llllll rl/fl/l April 15,, 1941. E MURRAY ETAL Re.21,772

BOILER AND THE LIKE Original 'i iled June 13 1924 3 Sheets-Sheet 2 77/019145 E. MUEAAYJ; area/far:

M ATTORNEYS Reissued Apr. 15, 1941 301mm AND THE LIKE Thomas E. Murray, deceased, late of Brooklyn, N. Y., by Joseph'B. Murray and Thomas E. Murray, Jr., executors, Brooklyn, N. Y., and John H, Lawrence, Bronxville, N.'Y., assignors to Metropolitan Engineering Company, a corporation of New York Original No. 1,993,071, dated March 5, 1935, Se-

rial No. 719,696, June 13, 1924. Application forreissue March 4, 1937, Serial No. 128,972

14 Claims.

In certain previous applications for patent of Thomas E. Murray (Serial No. 678,443, Patent No. 1,953,768 and others) there are described furnaces with walls of tubular or hollow construc.

tion for carrying water to be. heated or boiled or steam to be superheated, these being referred to herein generally as water walls or walls of water tubes. It is important in connection with such water walls, particularly by reason of the great heat to which they are exposed in the furnace, the radiant heat of the burning fuel, that there be a free and easy circulation through such walls or tubes. The present invention is directed particularly to the circulating system used in connection with such water walls.

The accompanying drawings illustrate embodiments of the invention. l v

Fig. 1 is a longitudinal vertical section of a boiler; Fig. 2 is a. perspective view of a pair of water walls and their connections; Fig. 3 is a perspective view of a detail of the tubes forming the water walls; Figs. 4 and 5 are views similar to Fig, 1 illustrating modifications.

Referring to the embodiment of the invention illustrated, the furnace is provided with a stoker grate I, a front wall 2, rear wall 3, and side walls enclosing a combustion chamber 4.

Above the combustion chamber are sets'of the with top and bottom headers II and I2, respectively. The water is introduced through the bottom header and is heated and passes out through the top header and thence to a steam drum. The steam is taken off from the drum and the water therein returned to the bottom header. Where these water walls are used in connection with the ordinary inclined sets of tubes, a commonsteam drum l3 may be used for-the several sets of tubes. v,

The water from the drum l3 passes down through pipes I4 and through headers I5 and ii in succession to the lower ends of the inclined tubes. Themixed water and steam from these inclined tubes passes by way of" headers ll and I8 and pipes l9 back to the steam drum 13. Ordinarily, below the header it there is located a mud drum 20 to collect sediment from the water, where it can be cleaned out from time to time.

According to Fig. 1, the area of the pipes ll and headers l5 and Hi is made great enough to usual inclined water tubes 5, 6 and I constituting the ordinary boiler and superheater tubes, with baflles for properly directing the gases of combustion around the tubes and out finally by the smoke pipe 8 to the exhaust fan or stack.

The inclined, approximately horizontal, tubes are supplemented by sets of vertical tubes 9, arranged at the sides of the combustion chamber of the furnace and exposed directly to the radiant heat of the burning fuel. Preferably, as described in the previous applications above referred to, the tubes 9 are of the kind illustrated in Fig. 3, with longitudinal fins l0 secured to the sides of the tubes and overlapping each other, so as to cover the space between the tubes. These fins provide in effect a greatly increased surface of conducting material exposed to the heat of the furnace and transmitting such heat by conduc-v tion to the waterwithin the tubes, and thus greatly increase the efllciency of the boiler asa whole.

Because of the high rate at which the 'water in these tubes is converted into steam, it is particularly important for efiiciency and also to prevent explosions, that they be provided with a reliable circulating system. The set ofvertical tubes at each side of the furnace is connected permit a free circulation of water for the incllned tubes and also of the water for the vertical tubes or water walls of the furnace. The water passes then from the header i6 through a number of branches lGa (Fig. 2) to the mud drum 2!), and thence from the drum through downwardly inclined pipes 2| to the back of the furnace, and thence by approximately vertical pipes 22 to the rear ends of the bottom headers I2. From the top headers l I the water and steam passes out of the front end through vertical pipes 23 and thence to a. header or cross-pipe, which has a number of small branches 25 leading to the steam drum ii.

The vertical tubes are thus provided each with a complete circulating system which will not be interfered with by any irregularity in the other;

4 v and the circulating systems for these water walls of the furnace are complete so as not to be interfered with by any imperfection in the circulation of the regular inclined tubes. At the lower ends of the headers l2 there are shown in Fig. 2 flanges 26 for connecting to the boiler blow-off pipe. There are also shown openings 21 through the lower part of the water walls, for stoker doors. Various other usual or suitable details may be added. 7

If it be desired, the water supply from the drum I3 to the furnace water walls may be independent of that to the regular horizontal tubes. Fig. 4 illustrates such an arrangement. A pair'of separate water pipes 28 parallel the pipes l4 and headers l5 and I 6 and carries water directly to Il leads through the pipes 23. 24 and 25 to an independent drum 29, from which the steam is taken off at the top and from which the water flows out at the bottom through a pair of pipes 30 to the drum 20 which supplies thewater walls as before.

The passing of the water pipe 2| around to the back of the furnace and then down is intended to permit a certain amount of expansion without injury to the Joints. The admission of water to one end of the headers I2 and the escape of the water and steam from the opposite end of headers H serve to aid in the distribution of the water through the several tubes 9, and tend to prevent any short circuiting of the circulating fluid through only one or a few of the vertical tubes.

Feed water may be admitted at any desired point, as for example at 3|, Figs. 1 and 2. The steam from the drum is taken oil by a pipe 32 (Fig. 1); and by pipes 32 and 33 (Fig. 5).

The stoker for the grate l is of the under feed type. The details are well known. The coal is fed to the grate and forced slowly upwardto the top of the mass on the grate. Thus the coal is preheated or partially coked before reaching the exposed surface of the mass where it burns at a very high temperature. The temperature in fact experience frequent. repairs and replacements of such refractory walls have been necessitated. By the provision of vertical tubes for the side walls or linings thereof, it has been found possible to operate with under feed stokers with practically is so high that no ordinary refractory walls are capable of withstanding it very long, and in our no deterioration of the side walls. And such stokers may be operated at ahigh speed in order an increased heating surface compared with the ordinary boiler, and utilize the intense radiant heat which is due to the high temperature, the vertical position of the tubes facilitating the necessary rapid circulation. These side walls of vertical tubes, therefore, permit the use withefliciency of the very high temperatures produced at the surface of the burning fuel of the under feed stoker, and permit this without injury to the side walls and with an enormously increased capacity for a boiler of given size.

Though we have described with great particularity of detailcertain embodiments of our invention, yet it is not to be understood therefrom that the invention is restricted to the particular embodiments described. Various modifications may be made by those skilled in the art, without .tubcs,a'steamdrumcommunicatingwiththe headers at the outlet ends ofsaid tubes, and a common drum communicating with the headers at the inlet ends of the horizontal tubes and also with the headers at the inlet ends of the vertical tubes.

2. A boiler having a furnace with a wall composed of substantially vertical water tubes spaced apart from each other with longitudinal ilnsextending into the spaces between the tubes so as to provide additional heating surface, said tubes being at the sides of the furnace and being exposed on one side only to the direct radiant heat of the burning fuel, headers at the opposite ends of said tubes, a steam drum and connections from the water space of said drum to the lower end of said headers and from the upper one of said headers to the steam'space of said drum.

- 3. A boiler having a furnace with a wall of sub stantially vertical water tubes at the sides of the furnace and being exposed on one side only to the radiant heat of the burning fuel, headers at the opposite ends of said tubes and a steam drum, said drum having an outlet from its water space communicating with the lower one of said headers and an inlet to its steam space communicating with the upper one of said headers, in combination with water tubes above the combustion chamber and about which the combustion gases are conveyed and a circulating system therefor; the circulating pipes for the wall of vertical'tubes beingseparate from those for the overhead tubes.

4. A boiler having a furnace with a wall of vertical water tubes and top and bottom headers, a drum above one end of said wall, the top header having an outlet at the same end of the wall which outlet communicates with said drum, the bottom header having an inlet at the opposite end of the wall, and a water pipe extending across the length of the wall and leading from the drum to the inlet end of the bottom header.

5. A boiler having a furnace with side walls of vertical water tubes and top and bottom headers. a steam drum disposed transversely of the vertical planes of said walls at one end of the furnace, the top headers having their only outlets at the same end of the furnace, which outlets communicate with the steam drum, the bottom headers having their only inlets at the opposite end of the furnace, and water pipes extending across the length of said walls and leading from the drum to the inlets oi the bottom headers.

v6. A boiler having a furnace with a wall of substantially vertical water tubes and top and bottom horizontally extending headers and having a steam drum, the top header having its only outlet at one end, which outlet communicates with the steam drum, and having inlets along its length from the several vertical tubes, the bottom header having its only inlet at one end, opposite to the outlet end of the top header, which inlet communicates with the steam drum, and having outlets along its length to the several vertical tubes so as to produce a rapid circulation vertical tubes, so as to produce a rapid circulation well distributed among said tubes.

8. A boiler having a furnace with a wall composed of substantially vertical water tubes spaced apart from. each other with metallic closure pieces extending across the spaces between the tubes and in heat conducting contact with the tubes, said tubes being at the sides of the furnace and being exposed on one side only to the direct radiant heat of the burning fuel, headers at the opposite ends of said tubes, a steam drum, and connections from the water space of said drum to the lower one of said headers and from the upper one of said headers to the steam space of said drum. 7

9. A boiler having a furnace with a wall of water tubes at the sides of the furnace exposed on one side to the radiant heat of the burning so that the tubes are heated by convection, and

a circulating systemv therefor, the circulating pipes for the wall of radiantly heated tubes being separate from those for the convection heated tubes.

10. The boiler of claim 9, the radiantly heated tubes being vertical.

11. The boiler of claim 9, the radiantly heated tubes being vertical and the convection heated tubes being horizontal and located above the radiantly heated tubes.

1-2. A boiler having a furnace with a wall composed of substantially vertical water tubes, said tubes being at the sides of the furnace and being exposed atone side onlyto the radiant heat of the burning fuel, headers at the opposite ends of said tubes, a steam drum and connections from the water space of said drum to the lower one of said headers and-from the upper one of said headers to the steam space of said drum.

13. The'boiler of claim 12, said water tubes constituting parts of a metal wall extending completely across the width and exposed to the radiant heat of the burning fuel.

14.'The boiler of claim 12, said water tubes constituting parts of a, metal wall extending completely across the 'width and exposed to, the radiant heat of the burning fuel, said vertical tubes being shielded attheir lower ends from the fire. JOSEPH B. MURRAY. THOMAS E. MURRAY, JR. Executors of the Estate of Thomas E. Murray,.

- Deceased. JOHN H. LAWRENCE. 

